Human Stomach Cells Research Articles

Oral infectivity through carnivorism in murine model of Trypanosoma cruzi infection.

Oral transmission of T. cruzi is probably the most frequent transmission mechanism in wild animals. This observation led to the hypothesis that consuming raw or undercooked meat from animals infected with T. cruzi may be responsible for transmitting the infection. Therefore, the general objective of this study was to investigate host-pathogen interactions between the parasite and gastric mucosa and the role of meat consumption from infected animals in the oral transmission of T. cruzi. Cell infectivity assays were performed on AGS cells in the presence or absence of mucin, and the roles of pepsin and acidic pH were determined. Moreover, groups of five female Balb/c mice were fed with muscle tissue obtained from mice in the acute phase of infection by the clone H510 C8C3hvir of T. cruzi, and the infection of the fed mice was monitored by a parasitemia curve. Similarly, we assessed the infective capacity of T. cruzi trypomastigotes and amastigotes by infecting groups of five mice Balb/c females, which were infected orally using a nasogastric probe, and the infection was monitored by a parasitemia curve. Finally, different trypomastigote and amastigote inoculums were used to determine their infective capacities. Adhesion assays of T. cruzi proteins to AGS stomach cells were performed, and the adhered proteins were detected by western blotting using monoclonal or polyclonal antibodies and by LC-MS/MS and bioinformatics analysis. Trypomastigote migration in the presence of mucin was reduced by approximately 30%, whereas in the presence of mucin and pepsin at pH 3.5, only a small proportion of parasites were able to migrate (∼6%). Similarly, the ability of TCTs to infect AGS cells in the presence of mucin is reduced by approximately 20%. In all cases, 60-100% of the animals were fed meat from mice infected in the acute phase or infected with trypomastigotes or amastigotes developed high parasitemia, and 80% died around day 40 post-infection. The adhesion assay showed that cruzipain is a molecule of trypomastigotes and amastigotes that binds to AGS cells. LC-MS/MS and bioinformatics analysis, also confirmed that transialidase, cysteine proteinases, and gp63 may be involved in TCTs attachment or invasion of human stomach cells because they can potentially interact with different proteins in the human stomach mucosa. In addition, several human gastric mucins have cysteine protease cleavage sites. Then, under our experimental conditions, consuming meat from infected animals in the acute phase allows the T. cruzi infection. Similarly, trypomastigotes and amastigotes could infect mice when administered orally, whereas cysteinyl proteinases and trans-sialidase appear to be relevant molecules in this infective process.

A human stomach cell type transcriptome atlas

BackgroundThe identification of cell type-specific genes and their modification under different conditions is central to our understanding of human health and disease. The stomach, a hollow organ in the upper gastrointestinal tract, provides an acidic environment that contributes to microbial defence and facilitates the activity of secreted digestive enzymes to process food and nutrients into chyme. In contrast to other sections of the gastrointestinal tract, detailed descriptions of cell type gene enrichment profiles in the stomach are absent from the major single-cell sequencing-based atlases.ResultsHere, we use an integrative correlation analysis method to predict human stomach cell type transcriptome signatures using unfractionated stomach RNAseq data from 359 individuals. We profile parietal, chief, gastric mucous, gastric enteroendocrine, mitotic, endothelial, fibroblast, macrophage, neutrophil, T-cell, and plasma cells, identifying over 1600 cell type-enriched genes.ConclusionsWe uncover the cell type expression profile of several non-coding genes strongly associated with the progression of gastric cancer and, using a sex-based subset analysis, uncover a panel of male-only chief cell-enriched genes. This study provides a roadmap to further understand human stomach biology.

Smart drug delivery against Helicobacter pylori: pectin-coated, mucoadhesive liposomes with antiadhesive activity and antibiotic cargo.

The first step in the development of Helicobacter pylori pathogenicity is the receptor-mediated adhesion to the gastric epithelium. Inhibition of outer membrane proteins of H. pylori (e.g. BabA) by antiadhesive drugs will contribute to reduced recolonization and infection. Pectin from apple inhibits the BabA and LPS-mediated adhesion of H. pylori to human stomach cells. Pectin-coated liposomes with encapsulated amoxicillin were characterized for polydispersity, zeta potential, encapsulation efficiency, stability, and amoxicillin release. Coated liposomes did not influence the viability of AGS and HT29-MTX cells up to 100 μg/mL but exert cytotoxicity against H. pylori at 10 μg/mL. Pectin-coating of liposomes provoked direct interaction and subsequent binding of the particles to surface structures of H. pylori, and interaction with mucus from porcine stomach and mucus secreted by HT29-MTX cells. Laser scanning microscopy of H. pylori and AGS cells together with liposomes indicated co-aggregation. The mucoadhesive effect seems interesting as stomach cells are covered by a mucus layer. H. pylori is able to penetrate and cross the mucin rapidly to reach pH-neutral epithelium to escape the acidic environment, followed by interaction with epithelial cells. In summary, all experimental evidence is consistent with a specific interaction of pectin-coated liposomes with mucins and surface structures of H. pylori. As the coated liposomes show mucoadhesion to the negatively charged mucins, docking to stomach mucin, mucus penetration, and recognition of and adhesion to H. pylori, they can be considered a novel type of multifunctional drug carriers for local antibiotic therapy against H. pylori. KEY POINTS: • Smart, multifunctional mucoadhesive liposomes • Specific targeting against BabA/LPS of Helicobacter pylori • Inhibition of bacterial adhesion of H. pylori to human host cells • Release of antibiotic cargo.

Abstract IA6: Lgr5 stem cell-based organoids in human disease

Abstract The intestinal epithelium is the most rapidly self-renewing tissue in adult mammals. We originally defined Lgr5 as a Wnt target gene, transcribed in colon cancer cells. Two knock-in alleles revealed exclusive expression of Lgr5 in cycling, columnar cells at the crypt base. Using lineage tracing experiments in adult mice, we found that these Lgr5+ve crypt base columnar cells (CBC) generated all epithelial lineages throughout life, implying that they represent the stem cell of the small intestine and colon. Lgr5 was subsequently found to represent an exquisitely specific and almost ‘generic’ marker for stem cells, including in hair follicles, kidney, liver, mammary gland, inner ear tongue and stomach epithelium. Single sorted Lgr5+ve stem cells can initiate ever-expanding crypt-villus organoids, or so called ‘mini-guts’ in 3D culture. The technology is based on the observation that Lgr5 is the receptor for a potent stem cell growth factor, R-spondin. Similar 3D cultures systems have been developed for the Lgr5+ve stem cells of human stomach, liver, pancreas, prostate and kidney. Using CRISPR/Cas9 technology, genes can be efficiently modified in organoids of various origins. Citation Format: Hans Clevers. Lgr5 stem cell-based organoids in human disease [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr IA6.

Gene Expression Analysis from the Normal Stomach Cells Treated with a Cancer Inducer N-methyl-N'-nitro-N-nitrosoguanidine, MNNG

N-methyl-N-nitro-N-nitrosoguanidine (MNNG) is a carcinogen made of modified guanine on which alkyl group is added on 6th oxygen. It has been used for inducing different types of cancers experimentally in vivo and in vitro. Stomach cancer might be the best well established particular cancer induced with MNNG. Comparative analysis of gene expression between normal stomach cell and MNNG-treated stomach cell could give much information to understand cancer formation in stomach. To this end, normal human stomach cells HS738 were treated with DMSO or MNNG. Genetic comparison was conducted with purified RNA from the treated cells for 6 hours or 24 hours. Total 13 genes were selected based on their high induction folds and comprehensible function to cancer formation. Some of the genes were cancer-promoting whereas the others were anti-cancer genes. These results could give important information of genetic changes in stomach cells during MNNG-induced stomach cancer formation.

Abstract IA04: Lgr5 stem cell-based organoids in human disease

Abstract The intestinal epithelium is the most rapidly self-renewing tissue in adult mammals. We originally defined Lgr5 as a Wnt target gene, transcribed in colon cancer cells. Two knock-in alleles revealed exclusive expression of Lgr5 in cycling, columnar cells at the crypt base. Using lineage tracing experiments in adult mice, we found that these Lgr5+ve crypt base columnar cells (CBC) generated all epithelial lineages throughout life, implying that they represent the stem cell of the small intestine and colon. Lgr5 was subsequently found to represent an exquisitely specific and almost ‘generic’ marker for stem cells, including in hair follicles, kidney, liver, mammary gland, inner ear tongue and stomach epithelium. Single sorted Lgr5+ve stem cells can initiate ever-expanding crypt-villus organoids, or so called ‘mini-guts’ in 3D culture. The technology is based on the observation that Lgr5 is the receptor for a potent stem cell growth factor, R-spondin. Similar 3D cultures systems have been developed for the Lgr5+ve stem cells of human stomach, liver, pancreas, prostate and kidney. Using CRISPR/Cas9 technology, genes can be efficiently modified in organoids of various origins. Citation Format: Hans Clevers. Lgr5 stem cell-based organoids in human disease. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr IA04.

Novel nuclear targeting coiled-coil protein of Helicobacter pylori showing Ca(2+)-independent, Mg(2+)-dependent DNase I activity.

HP0059, an uncharacterized gene of Helicobacter pylori, encodes a 284-aa-long protein containing a nuclear localization sequence (NLS) and multiple leucine-rich heptad repeats. Effects of HP0059 proteins in human stomach cells were assessed by incubation of recombinant HP0059 proteins with the AGS human gastric carcinoma cell line. Wild-type HP0059 proteins showed cytotoxicity in AGS cells in a concentration-dependent manner, whereas NLS mutant protein showed no effect, suggesting that the cytotoxicity is attributed to host nuclear localization. AGS cells transfected with pEGFP-HP0059 plasmid showed strong GFP signal merged to the chromosomal DNA region. The chromosome was fragmented into multiple distinct dots merged with the GFP signal after 12 h of incubation. The chromosome fragmentation was further explored by incubation of AGS chromosomal DNA with recombinant HP0059 proteins, which leaded to complete degradation of the chromosomal DNA. HP0059 protein also degraded circular plasmid DNA without consensus, being an indication of DNase I activity. The DNase was activated by MgCl2, but not by CaCl2. The activity was completely blocked by EDTA. The optimal pH and temperature for DNase activity were 7.0-8.0 and 55°C, respectively. These results indicate that HP0059 possesses a novel DNase I activity along with a role in the genomic instability of human gastric cells, which may result in the transformation of gastric cells.

Abstract IA12: Lgr5 stem cell-based organoids in human disease

Abstract The intestinal epithelium is the most rapidly self-renewing tissue in adult mammals. We originally defined Lgr5 as a Wnt target gene, transcribed in colon cancer cells. Two knock-in alleles revealed exclusive expression of Lgr5 in cycling, columnar cells at the crypt base. Using lineage tracing experiments in adult mice, we found that these Lgr5+ve crypt base columnar cells (CBC) generated all epithelial lineages throughout life, implying that they represent the stem cell of the small intestine and colon. Lgr5 was subsequently found to represent an exquisitely specific and almost ‘generic’ marker for stem cells, including in hair follicles, kidney, liver, mammary gland, inner ear tongue and stomach epithelium. Single sorted Lgr5+ve stem cells can initiate ever-expanding crypt-villus organoids, or so called ‘mini-guts’ in 3D culture. The technology is based on the observation that Lgr5 is the receptor for a potent stem cell growth factor, R-spondin. Similar 3D cultures systems have been developed for the Lgr5+ve stem cells of human stomach, liver, pancreas, prostate and kidney. Using CRISPR/Cas9 technology, genes can be efficiently modified in organoids of various origins. Citation Format: Hans Clevers. Lgr5 stem cell-based organoids in human disease. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr IA12.

Gastroprotection as an example: Antiadhesion against Helicobacter pylori, anti-inflammatory and antioxidant activities of aqueous extracts from the aerial parts of Lippia integrifolia Hieron

Ethnopharmacological relevanceThe aerial parts of Lippia integrifolia (Gris.) Hieronymus (Verbenaceae), known as incayuyo, are used by the peasant population of Argentina for treatment of diseases related to a gastrointestinal system, mainly for inflammation of the stomach and have also been included into the Argentina Food Code. This study aimed to investigate the phytochemical profile of hydrophilic extracts from the herbal material by LC−MS and to evaluate potential pharmacological mechanisms rationalizing the traditional use of incayuyo aqueous extracts potential anti-inflammatory treatment of gastrointestinal disorders. Materials and methodsPhytochemical profiling: LC−MS of an aqueous decoction. Antiadhesive effects against Helicobacter pylori: in vitro FACS assay using FITC-labeled bacteria and AGS human stomach cells. Influence of extracts on stomach cells and RAW 264.7 macrophages: MTT viability assay and BrdU proliferation ELISA. Influence of extracts on IL-6 and IL-8 secretion from stomach cells was quantitated by ELISA after infection of the cells with Helicobacter pylori. Influence of test extracts on macrophages: phagocytosis of FITC-labeled Zymosan particles and NO production. Antioxidative capacity: DPPH assay and O2-induced caroten oxidation. ResultsLC−MS profiling indicated the presence of compounds 1−20 with flavonoid hexosides, phenylethanoides (acteoside, isoacteoside) and sesquiterpenes [(epi)lippidulcine, peroxylippidulcine] in the decoction extract and subfraction PhF. The extract exhibits strong in vitro antioxidative capacity and inhibited adhesion of Helicobacter pylori to stomach cells up to 40%, while an EtOH-soluble fraction showed inhibition rates of up to 60%. Decoction increased the cellular viability of AGS cells significantly at >10μg/mL, while proliferation rate was not influenced. Helicobacter pylori induced IL-8 secretion was significantly reduced by coincubation of AGS cells with the extracts. Aqueous extracts stimulated phagocytosis rate of macrophages and inhibited the LPS-induced NO-secretion. ConclusionsThe traditional use of aqueous extracts from Lippia integrifolia for gastric inflammation seems to be rationalized: besides anti-inflammatory effects on stomach cells antiadhesive properties of the extracts against the main bacterial inductor of gastritis Helicobacter pylori were identified. Additional effects for stimulation of innate immunity and potential radical scavenging effects may additionally contribute to the activity of the extracts.

The chemopreventive effect of β-cryptoxanthin from mandarin on human stomach cells (BGC-823)

β-Cryptoxanthin, a provitaminic carotenoid, present in many fruits and vegetables, has been associated with decreased risk of chronic diseases, including cancer. The influence of β-cryptoxanthin derived from mandarin on the proliferation of the stomach tumor cell line BGC-823 was tested using MTT and cell count assay at 72h and dose–response (from 0.01 to 20μM). β-Cryptoxanthin suppressed the cell migration by the scratch assay. Furthermore, β-cryptoxanthin induced an accumulation of cells in the G1/G0 phase of the cell cycle (as detected by flow cytometry), which was in accordance with an increased expression of p21 and down regulations of cyclin D1 and cyclin E, detected by Western blot analysis, and β-cryptoxanthin increased the mRNA levels of retinoic acid receptor β (RARβ) with the treatment at 10μM for 24h. Collectively, the above findings suggest that β-cryptoxanthin could be therapeutic in the treatment of stomach cancer cell in vitro.

Measurement of the Intracellular pH in Human Stomach Cells: A Novel Approach To Evaluate the Gastric Acid Secretory Potential of Coffee Beverages

As the consumption of coffee beverages sometimes is reported to cause gastric irritation, for which an increased stomach acid secretion is one of the promoting factors, different processing technologies such as steam-treatment have been developed to reduce putative stomach irritating compounds. There is evidence-based data neither on the effect of detailed processing variations nor on individual coffee components affecting the proton secretory activity (PSA). This work aimed at developing a screening model suitable for investigating the effects of commercial coffee beverages and components thereof on human parietal cells. Human gastric cancer cells (HGT-1) were treated with reconstituted freeze-dried coffee beverages prepared from customary coffee products such as regular coffee (RC, n = 4), mild bean coffee (MBC, n = 5), stomach friendly coffee (SFC, n = 4), and SFC decaffeinated (SFCD, n = 3). PSA was analyzed by flow cytometry using the pH-sensitive dye SNARF-AM. Treatment of the cells with MBC did not result in a PSA different from RC treatment (p <or= 0.07), whereas cells treated with SFC (p <or= 0.04) or SFCD (p <or= 0.03) showed a significantly lower PSA than those treated with RC. Quantitative and principle component analysis of putative stomach irritating compounds revealed significantly reduced contents of (beta)N-alkanoyl-5-hydroxytryptamides, caffeine, N-methylpyridinium, and catechol in SFCD compared to RC. However, none of these compounds seem to act as the sole key bioactive reducing the PSA of SFCD, since their contents in MBC and SFC samples were not different from those in RC samples, although the PSA of these beverages was significantly lower than that of reconstituted freeze-dried RC beverage.

An ethnopharmacological survey and in vitro confirmation of ethnopharmacological use of medicinal plants used for wound healing in Bosomtwi-Atwima-Kwanwoma area, Ghana

Aims of the study Wounds represent a major health burden and drain on healthcare resources in the world including Ghana and Africa. The majority of the people of Ghana and Africa still patronize traditional medicine for their health needs including various forms of wounds. The aim of this study is the identification of medicinal plants, type of wounds, dosage forms and collection methods used traditionally in treating wounds in the Bosomtwi-Atwima-Kwanwoma district, Ghana. In vitro screening of selected extracts from these plants on cell physiology of human dermal fibroblasts and keratinocytes was to be performed. Materials and methods Validated questionnaires were administered to 78 traditional healers in 54 communities of the district. Interviews and structured conversations were used to administer the questionnaires. Selected herbal material dominantly used by the healers was collected, identified and aqueous and ethanolic extracts were investigated in vitro on influence on cell physiology of keratinocytes and dermal fibroblasts (MTT-, BrdU-, LDH-assay). Antioxidant activities of ethanolic extracts were determined by free radical scavenging activity. Antiadhesive activity against Helicobacter pylori on human stomach cells was investigated for extracts reported to be used for stomach ulcer treatment. Results The ethnopharmacological survey revealed 104 plants species belonging to 47 families. The detailed use of these plants is documented. Aqueous extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni influenced the mitochondrial activity and proliferation of dermal fibroblasts and keratinocytes significantly. Ethanolic extracts of selected plants exhibited strong antioxidant activities comparable to α-tocopherol. For Spathodea campanulata, Hoslundia opposita and Pycnanthus angolensis, which were reported by the healers to be used also for wound healing in case of stomach ulcers, strong antiadhesive activity against Helicobacter pylori was demonstrated, while the extracts did not exhibit any direct cytotoxicity against the bacterium. Conclusions Traditional use of many wound-healing plants from Ghana can be well rationalized by the in vitro investigation of aqueous extracts. E.g. extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni exhibited significant influence on the cell viability and proliferation of keratinocytes and dermal fibroblasts.

Helicobacter pylori heat shock protein B (HspB) localizes in vivo in the gastric mucosa and MALT lymphoma

Heat shock protein B (HspB) is one of the dominant proteins recognized by most Helicobacter pylori-infected persons and is being considered as potential candidates for subunit vaccines. In the present study we describe the generation of an antibody against HspB and its use in immunohistochemical assays on gastric biopsies. We have demonstrated that our rabbit polyclonal antibody against HspB did not recognize any protein in lysates from a lung human epithelial cell (H1299) line and did not cross-react with the other members of human heat shock proteins. Secondly, we have observed that in gastric biopsies, HspB immunostaining was present inside the cytoplasm of human epithelial cells with a particular localization in the apical portion of gastric epithelial cells other than in the extracellular spaces among gastric cells of human stomach. Finally, we have demonstrated a cytoplasmic HspB immunostaining in groups of neoplastic cells of MALT lymphoma. In conclusion, our observations suggest a possible involvement of HspB in the pathogenesis of H. pylori-related pathologies such as gastritis, ulcer and gastric cancer.

Effects of Fucoidan from Mozuku on Human Stomach Cell Lines

Cladosiphon okamuranus (Okinawamozuku) is a species of Mozuku known to contain the most fucoidan of any brown algae. Fucoidan is a sulfated hetero polysaccharide with various biological activities. We isolated and purified fucoidan from C. okamuranus. The yield of fucoidan was 1.0% (w/w) based on wet algae from C. okamuranus. The sulfate content and molecular weight of the fucoidan were 9.8% (w/w) and approximately 3,200,000, respectively. We examined the effects of fucoidan on human stomach cell lines. Fucoidan from C. okamuranus showed an inhibitory effect on anticancer agent 5-fluorouracil (5-FU) in Hs 677.st normal stomach cells with minimum inhibition of the original effect of 5-FU in cancer cells. Furthermore, fucoidan from C. okamuranus showed growth inhibition of stomach cancer cells but did not show any effects on normal cells. Thus, fucoidan from Mozuku, especially C. okamuranus, may be useful for cancer therapy.

Expression of a candidate marker for progenitor cells, Musashi‐1, in the proliferative regions of human antrum and its decreased expression in intestinal metaplasia

Reliable makers for progenitor cells in the human stomach have not been elucidated. The aim of the present study was to clarify whether Musashi-1 (Msi-1), which has recently been proposed as a stem cell marker in mouse intestine, serves as a marker for progenitor cells in human stomach. Immunohistochemistry revealed that Msi-1+ cells were detected especially in the isthmus/neck region (the putative position of stem cells) of the adult antrum, but were limited to the basal regions of fetal pyloric glands during the early stages of development. These results suggest that Msi-1 expression occurs specifically in the stem cell-containing regions. Msi-1+ cells were intermingled with proliferating cell nuclear antigen (PCNA)+ cells in the isthmus/neck region of the adult antrum, but did not coexpress PCNA or Ki 67. Msi-1 expression overlapped partly with expression of MUC 5 AC and MUC 6, indicating that Msi-1+ cells retain some features of both foveolar and pyloric gland cell differentiation phenotypes. In contrast, Msi-1 expression in gastric glands showing intestinal metaplasia (IM) became weaker than that in the glands without IM. The specific expression of Msi-1 within the proliferative regions suggests that Msi-1 is a marker of cells with progenitor characteristics before active proliferation in human antrum.

Receptor-mediated targeting of lipobeads bearing acetohydroxamic acid for eradication of Helicobacter pylori

In the present context, phosphatidyl ethanolamine (PE) liposomes anchored polyvinyl alcohol (PVA) xerogel beads (lipobeads) bearing acetohydroxamic acid (AHA) was developed as a receptor-mediated drug delivery system for use in blocking adhesion of Helicobacter pylori and thereby preventing the sequelae of chronic gastric infections. PVA beads containing AHA were prepared by emulsification followed by low temperature crystallization method. Surface acylation with fatty acid chain was accomplished by treating PVA bare beads with palmitoyl chloride. The completion of this reaction was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) which confirmed the formation of an ester bond. Final formation of lipobeads was accomplished by combining acylated PVA beads with a PE liposome suspension. To confirm the specific binding propensity of lipobeads towards the PE specific surface receptors of H. pylori, we have performed in situ adherence assay and radiolabelling assay with human stomach cells and KATO-III cells, respectively. In both of these studies, pretreatment of H. pylori with lipobeads completely inhibited the adhesion of H. pylori to human stomach cells and KATO-III cells. These assays could serve as suitable in-vitro models for the study of binding efficacy of lipobeads with H. pylori surface receptors . In addition, the antimicrobial activity of the formulations was evaluated by growth inhibition (GI) studies with isolated H. pylori strain. The inhibitory efficacy of lipobeads was significantly higher compared to that of PVA bare beads. These results suggest that lipobeads could be a potential targeted drug delivery system in the treatment of H. pylori.

Receptor Mediated Targeting of Lectin Conjugated Gliadin Nanoparticles in the Treatment of Helicobacter pylori

The present work describes the potential for using lectin-conjugated gliadin nanoparticles as a means of locating and anchoring a drug delivery system on the carbohydrate receptors of Helicobacter pylori (H. pylori). Gliadin nanoparticles (GNP) bearing acetohydroxamic acid (AHA) were prepared by a desolvation method. Ulex Europaeus Agglutinin I (UEA I) and Conconavalin A (Con A) lectins were bound to GNP formulations by the two-stage carbodiimide coupling technique. Lectin-agglutination assay was performed to evaluate the binding efficacy of lectin formulations to carbohydrate receptors of H. pylori strains. Strong agglutination patterns were observed with mannose-specific Con A-GNP and α(L)-fucose specific UEA–GNP formulations. In situ adherence assay was performed to examine the efficacy of lectin formulations to inhibit the binding of H. pylori strains with human stomach cells. Lectin formulations completely inhibited the H. pylori binding. In addition, the antimicrobial activity of the formulations was evaluated by percent growth inhibition studies (%GI) by using isolated H. pylori strain. The inhibitory efficacy of UEA–GNP and Con A–GNP was approximately two-fold higher compared to GNP. These lectin-conjugated gliadin nanoparticles are found to be potential candidate for targeted drug delivery and are anticipated to be useful in the treatment of H. pylori.

Relation of Helicobacter pylori to mucins and mucous cells in human stomach.

Relation of Helicobacter pylori to mucins and mucous cells in human stomach.

7191 Electron microscopic study of association between helicobacter pylori and gsatric epithelial cells.

Backgrounds: To study pathophysiologic roles of Helicobacter pylori, we investigate the ultrastructural relation of Helicobacter pylori to the gastric epithelial cells. Subjects and Methods: Endoscopic biopsy of gastric antrum and body were performed from thirty-one patients(18men and 13women) with chronic gastritis. These specimens were processed and observed by transmission and scanning electron microscope(Hitachi H-600, Hitachi S- 450). Results: 1) Helicobacter pylori were spiral, coccoid, and intermediate or un-defined forms. 2)Most of the Helicobacter pylori were present in the mucus gel layer, on the surface of gastric epithelium and were common at the area around the junctional complexes. 3)Coccoid forms were most common in the mucosal layer. 4)The gastric epithelial cells show increased cytoplasmic electron density, few microvilli, disruption of apical membrane, presence of cell fragments in intercellular space and mucosal layer. Junctional complexes were frequently observed deep in the intercellular space between the cytoplasmic elevation filled with secretory granules. Complete destruction of junctional complex was not common. Conclusions: Helicobacter pylori had variable relations to the gastric epithelial cells in human stomach. These features may contribute to the pathogenic action of the organism.

Distribution of heme oxygenase 2 in nerves and c-kit(+) interstitial cells in human stomach.

Different populations of interstitial cells (ICs) may serve as gut pacemakers or as intermediaries between enteric nerves and smooth muscle cells. However, very little is known about the substances that ICs might use to communicate with other cells and no data are available in humans. Because carbon monoxide (CO) is emerging as a putative mediator in the regulation of gastrointestinal motility, this study examined the presence of heme oxygenase (HO2), the constitutive form of the enzyme for CO production, in human stomach with particular attention to ICs. The distribution of HO2 in nerves and ICs in human antrum was studied using specific antibodies. The immunostaining was observed using confocal laser scanning microscopy. HO2 immunoreactivity was found in myenteric neurons and nerve fibers supplying the circular muscle layer and in intramuscular c-kit(+) ICs, but not in c-kit(+) ICs surrounding the myenteric ganglia. The presence of HO2 in different cell types suggests that CO may serve as an intercellular messenger between myenteric neurons and ICs and between ICs and smooth muscle cells in human stomach.